1. Field of the Invention
The present invention pertains to a method for manufacturing an electrical contact element used to test an electronic device, and an electrical contact element manufactured thereby, and more particularly, the present invention relates to a method for manufacturing an electrical contact element capable of electrically testing an electronic device by being brought into contact with the electronic device to see whether the electronic device is in a normal state or not, and an electrical contact element manufactured thereby.
Further, the present invention relates to a method for manufacturing an electrical contact element capable of electrically testing an electronic device by being increased in its physical force due to the presence of an armrest, to see whether the electronic device is in a normal state or not, and an electrical contact element manufactured thereby.
2. Description of the Related Art
Generally, a semiconductor chip is realized on a semiconductor substrate by implementing a series of semiconductor manufacturing processes including an oxidization process, a diffusion process, an ion-implantation process, an etching process, a metalization process, and so on. Chips fabricated on semiconductor substrates are sorted into normal ones and defective ones through an electrical die sorting (EDS) test. Then, only the normal chips are placed under slicing and packaging processes.
At this time, in the EDS test, an electrical contact element such as a probe card is brought into contact with a pad of a semiconductor chip to apply thereto an electric signal, and then, by detecting an electric signal responsive to the applied electric signal, it is possible to see whether the chip is in a normal state or not.
Also, in the case of a flat panel display device such as a liquid crystal display (LCD) which is manufactured by implementing a series of flat panel display device manufacturing processes, an electrical contact element is brought into contact with a preselected portion of the flat panel display device to apply thereto an electric signal, and then, by detecting an electric signal responsive to the applied electric signal, it is confirmed whether the LCD panel is in a normal state or not.
These days, researches and developments have been made in an effort to ensure that the conventional electrical contact element used for testing normality of a semiconductor chip or a flat panel display such as an LCD and the like conforms to the recent trend toward a fine pitch in a highly integrated semiconductor device such as an 1G DRAM, has a rapid responding velocity to be used in a high frequency band, possesses a sufficient strength not to become worn by repeated contact, maintains a predetermined contact resistance to have an excellent electric conductivity, and has a sufficient over-drive (OD) characteristic.
Specifically, researches and developments have been made in an effort to ensure that production of particles on the electrical contact element is minimized while the electrical contact element is repeatedly brought into contact with the highly integrated semiconductor device, the electrical contact element has an excellent electric conductivity, and tip portions of a plurality of electrical contact elements can be simultaneously brought into contact with a semiconductor chip pad to sufficiently satisfy an over-drive scheme.
As shown in FIG. 1, in the conventional electrical contact element, a terminal of an electronic component 10 such as a printed circuit board (PCB) having formed thereon a predetermined circuit pattern, and the like, is connected with a post portion 12. The post portion 12 is connected with a beam portion 14, and, in turn, the beam portion 14 is connected with a tip portion 16.
At this time, the post portion 12, beam portion 14 and tip portion 16 are individually provided and connected with one with another by adhesive means. The beam portion 14 has a bar-shaped configuration of a constant width.
In particular, the tip portion 16 has a pyramid-shaped configuration which is four-cornered and has a pointed end.
Thus, the tip portion 16 of the electrical contact element is repeatedly brought into contact with a semiconductor chip pad by constant physical force F while having a desired OD characteristic, to apply a constant electric signal to the semiconductor chip and thereby confirm whether the semiconductor chip is in a normal state or not.
However, the conventional electrical contact element has a problem in that, since the tip portion has the pointed distal end, while the tip portion of the electrical contact element is repeatedly brought into contact with the pad of the semiconductor chip by constant physical force F, the tip portion is likely to pierce an oxide film formed on the pad and damage the pad, by which a defective proportion cannot but be increased when implementing subsequent semiconductor manufacturing processes such as a wire bonding process, and the like.
Further, due to the fact that the tip portion of the conventional electrical contact element is cornered several times at its side, while the tip portion is brought into contact with the pad of the semiconductor chip, the tip portion is apt to become worn and produce particles by itself, which contaminate the highly integrated semiconductor chip.
Also, because the tip portion of the electrical contact element has the pointed distal end, a contact area between the tip portion and the semiconductor chip pad cannot but be decreased, and thereby electric conductivity is reduced.
Moreover, while the electrical contact element must be brought into contact with the semiconductor chip pad by constant physical force F to secure the desired OD characteristic, since the tip portion has a short length, it is difficult to properly adjust the OD characteristic.
That is to say, while the plurality of electrical contact elements are provided on a probe card and arranged to define a predetermined contour, because the tip portion of the electrical contact element has a short length, it is difficult to properly adjust heights of the plural electrical contact elements in such a way as to accomplish the desired OD characteristic.
The above-described problems can also be caused by the development in structure or configuration of the tip portion.
Namely, tip portions which initially have a tungsten needle-shaped configuration have been developed to have a V-shaped or a pyramid-shaped configuration. The pyramid-shaped tip portion has been developed to have a truncated pyramid-shaped configuration.
The tungsten needle-shaped tip portion has a drawback in that, when pointing the distal end of the tip portion, since distal end pointing work is manually carried out, reproducibility and productivity of the tip portion are impaired. Also, due to the fact that the pyramid-shaped and truncated pyramid-shaped tip portions have angled corners, while the tip portions are repeatedly brought into contact with pads of semiconductor devices, the tip portions are likely to become worn on the corners. Therefore, it is necessary to relieve or remove sharpness of the corners.
As a consequence, as already aforementioned above, when repeatedly implementing the test for the plurality of electronic devices, due to the presence of particles produced on the pointed distal end and corners of the tip portions, it is necessary to frequently wash the tip portions, as a result of which the test cannot be implemented in a quick and continuous manner.
Furthermore, while the recently developed high-frequency type electronic devices are significantly affected by noise, as the tip portion becomes worn, a contact point cannot be uniformly formed, and thereby, reliability of the test cannot but be degraded.
For this reason, it is required to implement the test within a short period of time to increase productivity.
In addition, because the beam portion has the bar-shaped configuration, it cannot properly conform to the recent trend toward a fine pitch in a highly integrated semiconductor device. Also, when the electrical contact element is brought into contact with the pad of the semiconductor chip by the constant physical force F, stress is concentrated to a certain point on the beam portion and the beam portion is likely to be broken.
Besides, due to a small connection area between the beam portion and the tip portion, when the electrical contact element is brought into contact with the semiconductor chip pad by the constant physical force F, stress is concentrated to the connection area and the tip portion is likely to be broken.
Further, while it is necessary to increase the constant physical force F applied to the tip portion in conventional electronic device testing equipment to the extent that the desired OD characteristic is secured and the oxide film formed on the semiconductor chip pad may be pierced, there is caused a problem due to various negative factors owned by the conventional electrical contact element.
Concretely speaking, while, in order to increase the constant physical force F, a length of the beam portion should be shortened, if the length of the beam portion is shortened, it is difficult to accomplish the desired OD characteristic, and excessive stress may be locally applied to the beam portion and thereby the beam portion is likely to be broken.
Also, while it is required that the beam portion has predetermined elasticity, as the length of the beam portion is shortened, elasticity of the beam portion is decreased.